From 0e08f4df740ea2f48225069bd862d47748d5cde6 Mon Sep 17 00:00:00 2001 From: "Michael D. Adams" Date: Tue, 3 Jul 2007 09:34:44 +0000 Subject: [PATCH] Moved 'continuationToProc' into a separate file, 'CmmCPSGen.hs'. --- compiler/cmm/CmmCPS.hs | 452 +----------------------------------------- compiler/cmm/CmmCPSGen.hs | 475 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 476 insertions(+), 451 deletions(-) create mode 100644 compiler/cmm/CmmCPSGen.hs diff --git a/compiler/cmm/CmmCPS.hs b/compiler/cmm/CmmCPS.hs index 4394fb5..a95f4af 100644 --- a/compiler/cmm/CmmCPS.hs +++ b/compiler/cmm/CmmCPS.hs @@ -14,12 +14,10 @@ import CmmLive import CmmBrokenBlock import CmmProcPoint import CmmCallConv +import CmmCPSGen import CmmInfo import CmmUtils -import CgProf (curCCS, curCCSAddr) -import CgUtils (cmmOffsetW) -import Bitmap import ClosureInfo import MachOp import ForeignCall @@ -27,7 +25,6 @@ import CLabel import SMRep import Constants -import StaticFlags import DynFlags import ErrUtils import Maybes @@ -41,12 +38,6 @@ import Monad import IO import Data.List -import MachRegs (callerSaveVolatileRegs) - -- HACK: this is part of the NCG so we shouldn't use this, but we need - -- it for now to eliminate the need for saved regs to be in CmmCall. - -- The long term solution is to factor callerSaveVolatileRegs - -- from nativeGen into CPS - ----------------------------------------------------------------------------- -- |Top level driver for the CPS pass ----------------------------------------------------------------------------- @@ -221,50 +212,6 @@ cpsProc uniqSupply (CmmProc info ident params blocks) = info_procs -------------------------------------------------------------------------------- --- The format for the call to a continuation --- The fst is the arguments that must be passed to the continuation --- by the continuation's caller. --- The snd is the live values that must be saved on stack. --- A Nothing indicates an ignored slot. --- The head of each list is the stack top or the first parameter. - --- The format for live values for a particular continuation --- All on stack for now. --- Head element is the top of the stack (or just under the header). --- Nothing means an empty slot. --- Future possibilities include callee save registers (i.e. passing slots in register) --- and heap memory (not sure if that's usefull at all though, but it may --- be worth exploring the design space). - -continuationLabel (Continuation _ l _ _ _) = l -data Continuation info = - Continuation - info -- Left <=> Continuation created by the CPS - -- Right <=> Function or Proc point - CLabel -- Used to generate both info & entry labels - CmmFormals -- Argument locals live on entry (C-- procedure params) - Bool -- ^ True <=> GC block so ignore stack size - [BrokenBlock] -- Code, may be empty. The first block is - -- the entry point. The order is otherwise initially - -- unimportant, but at some point the code gen will - -- fix the order. - - -- the BlockId of the first block does not give rise - -- to a label. To jump to the first block in a Proc, - -- use the appropriate CLabel. - -data ContinuationFormat - = ContinuationFormat { - continuation_formals :: CmmFormals, - continuation_label :: Maybe CLabel, -- The label occupying the top slot - continuation_frame_size :: WordOff, -- Total frame size in words (not including arguments) - continuation_stack :: [Maybe LocalReg] -- local reg offsets from stack top - } - --- A block can be a continuation of a call --- A block can be a continuation of another block (w/ or w/o joins) --- A block can be an entry to a function - ----------------------------------------------------------------------------- collectNonProcPointTargets :: @@ -466,400 +413,3 @@ applyContinuationFormat formats (Continuation format = maybe unknown_block id $ lookup label formats unknown_block = panic "unknown BlockId in applyContinuationFormat" ------------------------------------------------------------------------------ -continuationToProc :: (WordOff, [(CLabel, ContinuationFormat)]) - -> CmmReg - -> [[Unique]] - -> Continuation CmmInfo - -> CmmTop -continuationToProc (max_stack, formats) stack_use uniques - (Continuation info label formals _ blocks) = - CmmProc info label formals (concat $ zipWith3 continuationToProc' uniques blocks (True : repeat False)) - where - curr_format = maybe unknown_block id $ lookup label formats - unknown_block = panic "unknown BlockId in continuationToProc" - curr_stack = continuation_frame_size curr_format - arg_stack = argumentsSize localRegRep formals - - param_stmts :: [CmmStmt] - param_stmts = function_entry curr_format - - gc_stmts :: [CmmStmt] - gc_stmts = - case info of - CmmInfo _ (Just gc_block) _ _ -> - gc_stack_check' stack_use arg_stack (max_stack - curr_stack) - CmmInfo _ Nothing _ _ -> - panic "continuationToProc: missing GC block" - CmmNonInfo (Just gc_block) -> - gc_stack_check' stack_use arg_stack (max_stack - curr_stack) - CmmNonInfo Nothing -> - panic "continuationToProc: missing non-info GC block" - --- At present neither the Cmm parser nor the code generator --- produce code that will allow the target of a CmmCondBranch --- or a CmmSwitch to become a continuation or a proc-point. --- If future revisions, might allow these to happen --- then special care will have to be take to allow for that case. - continuationToProc' :: [Unique] - -> BrokenBlock - -> Bool - -> [CmmBasicBlock] - continuationToProc' uniques (BrokenBlock ident entry stmts _ exit) is_entry = - prefix_blocks ++ [main_block] - where - prefix_blocks = - case gc_prefix ++ param_prefix of - [] -> [] - entry_stmts -> [BasicBlock prefix_id - (entry_stmts ++ [CmmBranch ident])] - - prefix_unique : call_uniques = uniques - toCLabel = mkReturnPtLabel . getUnique - - block_for_branch unique next - | (Just cont_format) <- lookup (toCLabel next) formats - = let - new_next = BlockId unique - cont_stack = continuation_frame_size cont_format - arguments = map formal_to_actual (continuation_formals cont_format) - in (new_next, - [BasicBlock new_next $ - pack_continuation False curr_format cont_format ++ - tail_call (curr_stack - cont_stack) - (CmmLit $ CmmLabel $ toCLabel next) - arguments]) - | otherwise - = (next, []) - - block_for_branch' :: Unique -> Maybe BlockId -> (Maybe BlockId, [CmmBasicBlock]) - block_for_branch' _ Nothing = (Nothing, []) - block_for_branch' unique (Just next) = (Just new_next, new_blocks) - where (new_next, new_blocks) = block_for_branch unique next - - main_block = BasicBlock ident (stmts ++ postfix_stmts) - prefix_id = BlockId prefix_unique - gc_prefix = case entry of - FunctionEntry _ _ _ -> gc_stmts - ControlEntry -> [] - ContinuationEntry _ _ _ -> [] - param_prefix = if is_entry - then param_stmts - else [] - postfix_stmts = case exit of - FinalBranch next -> - if (mkReturnPtLabel $ getUnique next) == label - then [CmmBranch next] - else case lookup (mkReturnPtLabel $ getUnique next) formats of - Nothing -> [CmmBranch next] - Just cont_format -> - pack_continuation False curr_format cont_format ++ - tail_call (curr_stack - cont_stack) - (CmmLit $ CmmLabel $ mkReturnPtLabel $ getUnique next) - arguments - where - cont_stack = continuation_frame_size cont_format - arguments = map formal_to_actual (continuation_formals cont_format) - FinalSwitch expr targets -> [CmmSwitch expr targets] - FinalReturn arguments -> - tail_call curr_stack - (CmmLoad (CmmReg spReg) wordRep) - arguments - FinalJump target arguments -> - tail_call curr_stack target arguments - - -- A regular Cmm function call - FinalCall next (CmmForeignCall target CmmCallConv) - results arguments _ _ -> - pack_continuation True curr_format cont_format ++ - tail_call (curr_stack - cont_stack) - target arguments - where - cont_format = maybe unknown_block id $ - lookup (mkReturnPtLabel $ getUnique next) formats - cont_stack = continuation_frame_size cont_format - - -- A safe foreign call - FinalCall next (CmmForeignCall target conv) - results arguments _ _ -> - target_stmts ++ - foreignCall call_uniques' (CmmForeignCall new_target conv) - results arguments - where - (call_uniques', target_stmts, new_target) = - maybeAssignTemp call_uniques target - - -- A safe prim call - FinalCall next (CmmPrim target) - results arguments _ _ -> - foreignCall call_uniques (CmmPrim target) - results arguments - -formal_to_actual reg = (CmmReg (CmmLocal reg), NoHint) - -foreignCall :: [Unique] -> CmmCallTarget -> CmmHintFormals -> CmmActuals -> [CmmStmt] -foreignCall uniques call results arguments = - arg_stmts ++ - saveThreadState ++ - caller_save ++ - [CmmCall (CmmForeignCall suspendThread CCallConv) - [ (id,PtrHint) ] - [ (CmmReg (CmmGlobal BaseReg), PtrHint) ] - CmmUnsafe, - CmmCall call results new_args CmmUnsafe, - CmmCall (CmmForeignCall resumeThread CCallConv) - [ (new_base, PtrHint) ] - [ (CmmReg (CmmLocal id), PtrHint) ] - CmmUnsafe, - -- Assign the result to BaseReg: we - -- might now have a different Capability! - CmmAssign (CmmGlobal BaseReg) (CmmReg (CmmLocal new_base))] ++ - caller_load ++ - loadThreadState tso_unique ++ - [CmmJump (CmmReg spReg) (map (formal_to_actual . fst) results)] - where - (_, arg_stmts, new_args) = - loadArgsIntoTemps argument_uniques arguments - (caller_save, caller_load) = - callerSaveVolatileRegs (Just [{-only system regs-}]) - new_base = LocalReg base_unique (cmmRegRep (CmmGlobal BaseReg)) KindNonPtr - id = LocalReg id_unique wordRep KindNonPtr - tso_unique : base_unique : id_unique : argument_uniques = uniques - --- ----------------------------------------------------------------------------- --- Save/restore the thread state in the TSO - -suspendThread = CmmLit (CmmLabel (mkRtsCodeLabel SLIT("suspendThread"))) -resumeThread = CmmLit (CmmLabel (mkRtsCodeLabel SLIT("resumeThread"))) - --- This stuff can't be done in suspendThread/resumeThread, because it --- refers to global registers which aren't available in the C world. - -saveThreadState = - -- CurrentTSO->sp = Sp; - [CmmStore (cmmOffset stgCurrentTSO tso_SP) stgSp, - closeNursery] ++ - -- and save the current cost centre stack in the TSO when profiling: - if opt_SccProfilingOn - then [CmmStore (cmmOffset stgCurrentTSO tso_CCCS) curCCS] - else [] - - -- CurrentNursery->free = Hp+1; -closeNursery = CmmStore nursery_bdescr_free (cmmOffsetW stgHp 1) - -loadThreadState tso_unique = - [ - -- tso = CurrentTSO; - CmmAssign (CmmLocal tso) stgCurrentTSO, - -- Sp = tso->sp; - CmmAssign sp (CmmLoad (cmmOffset (CmmReg (CmmLocal tso)) tso_SP) - wordRep), - -- SpLim = tso->stack + RESERVED_STACK_WORDS; - CmmAssign spLim (cmmOffsetW (cmmOffset (CmmReg (CmmLocal tso)) tso_STACK) - rESERVED_STACK_WORDS) - ] ++ - openNursery ++ - -- and load the current cost centre stack from the TSO when profiling: - if opt_SccProfilingOn - then [CmmStore curCCSAddr - (CmmLoad (cmmOffset (CmmReg (CmmLocal tso)) tso_CCCS) wordRep)] - else [] - where tso = LocalReg tso_unique wordRep KindNonPtr -- TODO FIXME NOW - - -openNursery = [ - -- Hp = CurrentNursery->free - 1; - CmmAssign hp (cmmOffsetW (CmmLoad nursery_bdescr_free wordRep) (-1)), - - -- HpLim = CurrentNursery->start + - -- CurrentNursery->blocks*BLOCK_SIZE_W - 1; - CmmAssign hpLim - (cmmOffsetExpr - (CmmLoad nursery_bdescr_start wordRep) - (cmmOffset - (CmmMachOp mo_wordMul [ - CmmMachOp (MO_S_Conv I32 wordRep) - [CmmLoad nursery_bdescr_blocks I32], - CmmLit (mkIntCLit bLOCK_SIZE) - ]) - (-1) - ) - ) - ] - - -nursery_bdescr_free = cmmOffset stgCurrentNursery oFFSET_bdescr_free -nursery_bdescr_start = cmmOffset stgCurrentNursery oFFSET_bdescr_start -nursery_bdescr_blocks = cmmOffset stgCurrentNursery oFFSET_bdescr_blocks - -tso_SP = tsoFieldB oFFSET_StgTSO_sp -tso_STACK = tsoFieldB oFFSET_StgTSO_stack -tso_CCCS = tsoProfFieldB oFFSET_StgTSO_CCCS - --- The TSO struct has a variable header, and an optional StgTSOProfInfo in --- the middle. The fields we're interested in are after the StgTSOProfInfo. -tsoFieldB :: ByteOff -> ByteOff -tsoFieldB off - | opt_SccProfilingOn = off + sIZEOF_StgTSOProfInfo + fixedHdrSize * wORD_SIZE - | otherwise = off + fixedHdrSize * wORD_SIZE - -tsoProfFieldB :: ByteOff -> ByteOff -tsoProfFieldB off = off + fixedHdrSize * wORD_SIZE - -stgSp = CmmReg sp -stgHp = CmmReg hp -stgCurrentTSO = CmmReg currentTSO -stgCurrentNursery = CmmReg currentNursery - -sp = CmmGlobal Sp -spLim = CmmGlobal SpLim -hp = CmmGlobal Hp -hpLim = CmmGlobal HpLim -currentTSO = CmmGlobal CurrentTSO -currentNursery = CmmGlobal CurrentNursery - ------------------------------------------------------------------------------ --- Functions that generate CmmStmt sequences --- for packing/unpacking continuations --- and entering/exiting functions - -tail_call :: WordOff -> CmmExpr -> CmmActuals -> [CmmStmt] -tail_call spRel target arguments - = store_arguments ++ adjust_spReg ++ jump where - store_arguments = - [stack_put spRel expr offset - | ((expr, _), StackParam offset) <- argument_formats] ++ - [global_put expr global - | ((expr, _), RegisterParam global) <- argument_formats] - adjust_spReg = - if spRel == 0 - then [] - else [CmmAssign spReg (CmmRegOff spReg (spRel*wORD_SIZE))] - jump = [CmmJump target arguments] - - argument_formats = assignArguments (cmmExprRep . fst) arguments - -gc_stack_check' stack_use arg_stack max_frame_size = - if max_frame_size > arg_stack - then [CmmAssign stack_use (CmmRegOff spReg (-max_frame_size*wORD_SIZE))] - else [CmmAssign stack_use (CmmReg spLimReg)] - -- Trick the optimizer into eliminating the branch for us - -gc_stack_check :: BlockId -> WordOff -> [CmmStmt] -gc_stack_check gc_block max_frame_size - = check_stack_limit where - check_stack_limit = [ - CmmCondBranch - (CmmMachOp (MO_U_Lt $ cmmRegRep spReg) - [CmmRegOff spReg (-max_frame_size*wORD_SIZE), - CmmReg spLimReg]) - gc_block] - - --- TODO: fix branches to proc point --- (we have to insert a new block to marshel the continuation) - - -pack_continuation :: Bool -- ^ Whether to set the top/header - -- of the stack. We only need to - -- set it if we are calling down - -- as opposed to continuation - -- adaptors. - -> ContinuationFormat -- ^ The current format - -> ContinuationFormat -- ^ The return point format - -> [CmmStmt] -pack_continuation allow_header_set - (ContinuationFormat _ curr_id curr_frame_size _) - (ContinuationFormat _ cont_id cont_frame_size live_regs) - = store_live_values ++ set_stack_header where - -- TODO: only save variables when actually needed - -- (may be handled by latter pass) - store_live_values = - [stack_put spRel (CmmReg (CmmLocal reg)) offset - | (reg, offset) <- cont_offsets] - set_stack_header = - if needs_header_set && allow_header_set - then [stack_put spRel continuation_function 0] - else [] - - -- TODO: factor with function_entry and CmmInfo.hs(?) - cont_offsets = mkOffsets label_size live_regs - - label_size = 1 :: WordOff - - mkOffsets size [] = [] - mkOffsets size (Nothing:regs) = mkOffsets (size+1) regs - mkOffsets size (Just reg:regs) = (reg, size):mkOffsets (size + width) regs - where - width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE - -- TODO: it would be better if we had a machRepWordWidth - - spRel = curr_frame_size - cont_frame_size - continuation_function = CmmLit $ CmmLabel $ fromJust cont_id - needs_header_set = - case (curr_id, cont_id) of - (Just x, Just y) -> x /= y - _ -> isJust cont_id - --- Lazy adjustment of stack headers assumes all blocks --- that could branch to eachother (i.e. control blocks) --- have the same stack format (this causes a problem --- only for proc-point). -function_entry :: ContinuationFormat -> [CmmStmt] -function_entry (ContinuationFormat formals _ _ live_regs) - = load_live_values ++ load_args where - -- TODO: only save variables when actually needed - -- (may be handled by latter pass) - load_live_values = - [stack_get 0 reg offset - | (reg, offset) <- curr_offsets] - load_args = - [stack_get 0 reg offset - | (reg, StackParam offset) <- argument_formats] ++ - [global_get reg global - | (reg, RegisterParam global) <- argument_formats] - - argument_formats = assignArguments (localRegRep) formals - - -- TODO: eliminate copy/paste with pack_continuation - curr_offsets = mkOffsets label_size live_regs - - label_size = 1 :: WordOff - - mkOffsets size [] = [] - mkOffsets size (Nothing:regs) = mkOffsets (size+1) regs - mkOffsets size (Just reg:regs) = (reg, size):mkOffsets (size + width) regs - where - width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE - -- TODO: it would be better if we had a machRepWordWidth - ------------------------------------------------------------------------------ --- Section: Stack and argument register puts and gets ------------------------------------------------------------------------------ --- TODO: document - --- |Construct a 'CmmStmt' that will save a value on the stack -stack_put :: WordOff -- ^ Offset from the real 'Sp' that 'offset' - -- is relative to (added to offset) - -> CmmExpr -- ^ What to store onto the stack - -> WordOff -- ^ Where on the stack to store it - -- (positive <=> higher addresses) - -> CmmStmt -stack_put spRel expr offset = - CmmStore (CmmRegOff spReg (wORD_SIZE*(spRel + offset))) expr - --------------------------------- --- |Construct a -stack_get :: WordOff - -> LocalReg - -> WordOff - -> CmmStmt -stack_get spRel reg offset = - CmmAssign (CmmLocal reg) - (CmmLoad (CmmRegOff spReg (wORD_SIZE*(spRel + offset))) - (localRegRep reg)) -global_put :: CmmExpr -> GlobalReg -> CmmStmt -global_put expr global = CmmAssign (CmmGlobal global) expr -global_get :: LocalReg -> GlobalReg -> CmmStmt -global_get reg global = CmmAssign (CmmLocal reg) (CmmReg (CmmGlobal global)) - diff --git a/compiler/cmm/CmmCPSGen.hs b/compiler/cmm/CmmCPSGen.hs new file mode 100644 index 0000000..b2c4305 --- /dev/null +++ b/compiler/cmm/CmmCPSGen.hs @@ -0,0 +1,475 @@ +module CmmCPSGen ( + -- | Converts continuations into full proceedures. + -- The main work of the CPS transform that everything else is setting-up. + continuationToProc, + Continuation(..), continuationLabel, + ContinuationFormat(..), +) where + +#include "HsVersions.h" + +import Cmm +import CLabel +import CmmBrokenBlock -- Data types only +import MachOp +import CmmUtils +import CmmCallConv + +import CgProf (curCCS, curCCSAddr) +import CgUtils (cmmOffsetW) +import SMRep +import ForeignCall + +import Constants +import StaticFlags +import Unique +import Maybe + +import Panic + +import MachRegs (callerSaveVolatileRegs) + -- HACK: this is part of the NCG so we shouldn't use this, but we need + -- it for now to eliminate the need for saved regs to be in CmmCall. + -- The long term solution is to factor callerSaveVolatileRegs + -- from nativeGen into CPS + +-- The format for the call to a continuation +-- The fst is the arguments that must be passed to the continuation +-- by the continuation's caller. +-- The snd is the live values that must be saved on stack. +-- A Nothing indicates an ignored slot. +-- The head of each list is the stack top or the first parameter. + +-- The format for live values for a particular continuation +-- All on stack for now. +-- Head element is the top of the stack (or just under the header). +-- Nothing means an empty slot. +-- Future possibilities include callee save registers (i.e. passing slots in register) +-- and heap memory (not sure if that's usefull at all though, but it may +-- be worth exploring the design space). + +continuationLabel (Continuation _ l _ _ _) = l +data Continuation info = + Continuation + info -- Left <=> Continuation created by the CPS + -- Right <=> Function or Proc point + CLabel -- Used to generate both info & entry labels + CmmFormals -- Argument locals live on entry (C-- procedure params) + Bool -- ^ True <=> GC block so ignore stack size + [BrokenBlock] -- Code, may be empty. The first block is + -- the entry point. The order is otherwise initially + -- unimportant, but at some point the code gen will + -- fix the order. + + -- the BlockId of the first block does not give rise + -- to a label. To jump to the first block in a Proc, + -- use the appropriate CLabel. + +data ContinuationFormat + = ContinuationFormat { + continuation_formals :: CmmFormals, + continuation_label :: Maybe CLabel, -- The label occupying the top slot + continuation_frame_size :: WordOff, -- Total frame size in words (not including arguments) + continuation_stack :: [Maybe LocalReg] -- local reg offsets from stack top + } + +-- A block can be a continuation of a call +-- A block can be a continuation of another block (w/ or w/o joins) +-- A block can be an entry to a function + +----------------------------------------------------------------------------- +continuationToProc :: (WordOff, [(CLabel, ContinuationFormat)]) + -> CmmReg + -> [[Unique]] + -> Continuation CmmInfo + -> CmmTop +continuationToProc (max_stack, formats) stack_use uniques + (Continuation info label formals _ blocks) = + CmmProc info label formals (concat $ zipWith3 continuationToProc' uniques blocks (True : repeat False)) + where + curr_format = maybe unknown_block id $ lookup label formats + unknown_block = panic "unknown BlockId in continuationToProc" + curr_stack = continuation_frame_size curr_format + arg_stack = argumentsSize localRegRep formals + + param_stmts :: [CmmStmt] + param_stmts = function_entry curr_format + + gc_stmts :: [CmmStmt] + gc_stmts = + case info of + CmmInfo _ (Just gc_block) _ _ -> + gc_stack_check' stack_use arg_stack (max_stack - curr_stack) + CmmInfo _ Nothing _ _ -> + panic "continuationToProc: missing GC block" + CmmNonInfo (Just gc_block) -> + gc_stack_check' stack_use arg_stack (max_stack - curr_stack) + CmmNonInfo Nothing -> + panic "continuationToProc: missing non-info GC block" + +-- At present neither the Cmm parser nor the code generator +-- produce code that will allow the target of a CmmCondBranch +-- or a CmmSwitch to become a continuation or a proc-point. +-- If future revisions, might allow these to happen +-- then special care will have to be take to allow for that case. + continuationToProc' :: [Unique] + -> BrokenBlock + -> Bool + -> [CmmBasicBlock] + continuationToProc' uniques (BrokenBlock ident entry stmts _ exit) is_entry = + prefix_blocks ++ [main_block] + where + prefix_blocks = + case gc_prefix ++ param_prefix of + [] -> [] + entry_stmts -> [BasicBlock prefix_id + (entry_stmts ++ [CmmBranch ident])] + + prefix_unique : call_uniques = uniques + toCLabel = mkReturnPtLabel . getUnique + + block_for_branch unique next + | (Just cont_format) <- lookup (toCLabel next) formats + = let + new_next = BlockId unique + cont_stack = continuation_frame_size cont_format + arguments = map formal_to_actual (continuation_formals cont_format) + in (new_next, + [BasicBlock new_next $ + pack_continuation False curr_format cont_format ++ + tail_call (curr_stack - cont_stack) + (CmmLit $ CmmLabel $ toCLabel next) + arguments]) + | otherwise + = (next, []) + + block_for_branch' :: Unique -> Maybe BlockId -> (Maybe BlockId, [CmmBasicBlock]) + block_for_branch' _ Nothing = (Nothing, []) + block_for_branch' unique (Just next) = (Just new_next, new_blocks) + where (new_next, new_blocks) = block_for_branch unique next + + main_block = BasicBlock ident (stmts ++ postfix_stmts) + prefix_id = BlockId prefix_unique + gc_prefix = case entry of + FunctionEntry _ _ _ -> gc_stmts + ControlEntry -> [] + ContinuationEntry _ _ _ -> [] + param_prefix = if is_entry + then param_stmts + else [] + postfix_stmts = case exit of + FinalBranch next -> + if (mkReturnPtLabel $ getUnique next) == label + then [CmmBranch next] + else case lookup (mkReturnPtLabel $ getUnique next) formats of + Nothing -> [CmmBranch next] + Just cont_format -> + pack_continuation False curr_format cont_format ++ + tail_call (curr_stack - cont_stack) + (CmmLit $ CmmLabel $ mkReturnPtLabel $ getUnique next) + arguments + where + cont_stack = continuation_frame_size cont_format + arguments = map formal_to_actual (continuation_formals cont_format) + FinalSwitch expr targets -> [CmmSwitch expr targets] + FinalReturn arguments -> + tail_call curr_stack + (CmmLoad (CmmReg spReg) wordRep) + arguments + FinalJump target arguments -> + tail_call curr_stack target arguments + + -- A regular Cmm function call + FinalCall next (CmmForeignCall target CmmCallConv) + results arguments _ _ -> + pack_continuation True curr_format cont_format ++ + tail_call (curr_stack - cont_stack) + target arguments + where + cont_format = maybe unknown_block id $ + lookup (mkReturnPtLabel $ getUnique next) formats + cont_stack = continuation_frame_size cont_format + + -- A safe foreign call + FinalCall next (CmmForeignCall target conv) + results arguments _ _ -> + target_stmts ++ + foreignCall call_uniques' (CmmForeignCall new_target conv) + results arguments + where + (call_uniques', target_stmts, new_target) = + maybeAssignTemp call_uniques target + + -- A safe prim call + FinalCall next (CmmPrim target) + results arguments _ _ -> + foreignCall call_uniques (CmmPrim target) + results arguments + +formal_to_actual reg = (CmmReg (CmmLocal reg), NoHint) + +foreignCall :: [Unique] -> CmmCallTarget -> CmmHintFormals -> CmmActuals -> [CmmStmt] +foreignCall uniques call results arguments = + arg_stmts ++ + saveThreadState ++ + caller_save ++ + [CmmCall (CmmForeignCall suspendThread CCallConv) + [ (id,PtrHint) ] + [ (CmmReg (CmmGlobal BaseReg), PtrHint) ] + CmmUnsafe, + CmmCall call results new_args CmmUnsafe, + CmmCall (CmmForeignCall resumeThread CCallConv) + [ (new_base, PtrHint) ] + [ (CmmReg (CmmLocal id), PtrHint) ] + CmmUnsafe, + -- Assign the result to BaseReg: we + -- might now have a different Capability! + CmmAssign (CmmGlobal BaseReg) (CmmReg (CmmLocal new_base))] ++ + caller_load ++ + loadThreadState tso_unique ++ + [CmmJump (CmmReg spReg) (map (formal_to_actual . fst) results)] + where + (_, arg_stmts, new_args) = + loadArgsIntoTemps argument_uniques arguments + (caller_save, caller_load) = + callerSaveVolatileRegs (Just [{-only system regs-}]) + new_base = LocalReg base_unique (cmmRegRep (CmmGlobal BaseReg)) KindNonPtr + id = LocalReg id_unique wordRep KindNonPtr + tso_unique : base_unique : id_unique : argument_uniques = uniques + +-- ----------------------------------------------------------------------------- +-- Save/restore the thread state in the TSO + +suspendThread = CmmLit (CmmLabel (mkRtsCodeLabel SLIT("suspendThread"))) +resumeThread = CmmLit (CmmLabel (mkRtsCodeLabel SLIT("resumeThread"))) + +-- This stuff can't be done in suspendThread/resumeThread, because it +-- refers to global registers which aren't available in the C world. + +saveThreadState = + -- CurrentTSO->sp = Sp; + [CmmStore (cmmOffset stgCurrentTSO tso_SP) stgSp, + closeNursery] ++ + -- and save the current cost centre stack in the TSO when profiling: + if opt_SccProfilingOn + then [CmmStore (cmmOffset stgCurrentTSO tso_CCCS) curCCS] + else [] + + -- CurrentNursery->free = Hp+1; +closeNursery = CmmStore nursery_bdescr_free (cmmOffsetW stgHp 1) + +loadThreadState tso_unique = + [ + -- tso = CurrentTSO; + CmmAssign (CmmLocal tso) stgCurrentTSO, + -- Sp = tso->sp; + CmmAssign sp (CmmLoad (cmmOffset (CmmReg (CmmLocal tso)) tso_SP) + wordRep), + -- SpLim = tso->stack + RESERVED_STACK_WORDS; + CmmAssign spLim (cmmOffsetW (cmmOffset (CmmReg (CmmLocal tso)) tso_STACK) + rESERVED_STACK_WORDS) + ] ++ + openNursery ++ + -- and load the current cost centre stack from the TSO when profiling: + if opt_SccProfilingOn + then [CmmStore curCCSAddr + (CmmLoad (cmmOffset (CmmReg (CmmLocal tso)) tso_CCCS) wordRep)] + else [] + where tso = LocalReg tso_unique wordRep KindNonPtr -- TODO FIXME NOW + + +openNursery = [ + -- Hp = CurrentNursery->free - 1; + CmmAssign hp (cmmOffsetW (CmmLoad nursery_bdescr_free wordRep) (-1)), + + -- HpLim = CurrentNursery->start + + -- CurrentNursery->blocks*BLOCK_SIZE_W - 1; + CmmAssign hpLim + (cmmOffsetExpr + (CmmLoad nursery_bdescr_start wordRep) + (cmmOffset + (CmmMachOp mo_wordMul [ + CmmMachOp (MO_S_Conv I32 wordRep) + [CmmLoad nursery_bdescr_blocks I32], + CmmLit (mkIntCLit bLOCK_SIZE) + ]) + (-1) + ) + ) + ] + + +nursery_bdescr_free = cmmOffset stgCurrentNursery oFFSET_bdescr_free +nursery_bdescr_start = cmmOffset stgCurrentNursery oFFSET_bdescr_start +nursery_bdescr_blocks = cmmOffset stgCurrentNursery oFFSET_bdescr_blocks + +tso_SP = tsoFieldB oFFSET_StgTSO_sp +tso_STACK = tsoFieldB oFFSET_StgTSO_stack +tso_CCCS = tsoProfFieldB oFFSET_StgTSO_CCCS + +-- The TSO struct has a variable header, and an optional StgTSOProfInfo in +-- the middle. The fields we're interested in are after the StgTSOProfInfo. +tsoFieldB :: ByteOff -> ByteOff +tsoFieldB off + | opt_SccProfilingOn = off + sIZEOF_StgTSOProfInfo + fixedHdrSize * wORD_SIZE + | otherwise = off + fixedHdrSize * wORD_SIZE + +tsoProfFieldB :: ByteOff -> ByteOff +tsoProfFieldB off = off + fixedHdrSize * wORD_SIZE + +stgSp = CmmReg sp +stgHp = CmmReg hp +stgCurrentTSO = CmmReg currentTSO +stgCurrentNursery = CmmReg currentNursery + +sp = CmmGlobal Sp +spLim = CmmGlobal SpLim +hp = CmmGlobal Hp +hpLim = CmmGlobal HpLim +currentTSO = CmmGlobal CurrentTSO +currentNursery = CmmGlobal CurrentNursery + +----------------------------------------------------------------------------- +-- Functions that generate CmmStmt sequences +-- for packing/unpacking continuations +-- and entering/exiting functions + +tail_call :: WordOff -> CmmExpr -> CmmActuals -> [CmmStmt] +tail_call spRel target arguments + = store_arguments ++ adjust_spReg ++ jump where + store_arguments = + [stack_put spRel expr offset + | ((expr, _), StackParam offset) <- argument_formats] ++ + [global_put expr global + | ((expr, _), RegisterParam global) <- argument_formats] + adjust_spReg = + if spRel == 0 + then [] + else [CmmAssign spReg (CmmRegOff spReg (spRel*wORD_SIZE))] + jump = [CmmJump target arguments] + + argument_formats = assignArguments (cmmExprRep . fst) arguments + +gc_stack_check' stack_use arg_stack max_frame_size = + if max_frame_size > arg_stack + then [CmmAssign stack_use (CmmRegOff spReg (-max_frame_size*wORD_SIZE))] + else [CmmAssign stack_use (CmmReg spLimReg)] + -- Trick the optimizer into eliminating the branch for us + +gc_stack_check :: BlockId -> WordOff -> [CmmStmt] +gc_stack_check gc_block max_frame_size + = check_stack_limit where + check_stack_limit = [ + CmmCondBranch + (CmmMachOp (MO_U_Lt $ cmmRegRep spReg) + [CmmRegOff spReg (-max_frame_size*wORD_SIZE), + CmmReg spLimReg]) + gc_block] + + +-- TODO: fix branches to proc point +-- (we have to insert a new block to marshel the continuation) + + +pack_continuation :: Bool -- ^ Whether to set the top/header + -- of the stack. We only need to + -- set it if we are calling down + -- as opposed to continuation + -- adaptors. + -> ContinuationFormat -- ^ The current format + -> ContinuationFormat -- ^ The return point format + -> [CmmStmt] +pack_continuation allow_header_set + (ContinuationFormat _ curr_id curr_frame_size _) + (ContinuationFormat _ cont_id cont_frame_size live_regs) + = store_live_values ++ set_stack_header where + -- TODO: only save variables when actually needed + -- (may be handled by latter pass) + store_live_values = + [stack_put spRel (CmmReg (CmmLocal reg)) offset + | (reg, offset) <- cont_offsets] + set_stack_header = + if needs_header_set && allow_header_set + then [stack_put spRel continuation_function 0] + else [] + + -- TODO: factor with function_entry and CmmInfo.hs(?) + cont_offsets = mkOffsets label_size live_regs + + label_size = 1 :: WordOff + + mkOffsets size [] = [] + mkOffsets size (Nothing:regs) = mkOffsets (size+1) regs + mkOffsets size (Just reg:regs) = (reg, size):mkOffsets (size + width) regs + where + width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE + -- TODO: it would be better if we had a machRepWordWidth + + spRel = curr_frame_size - cont_frame_size + continuation_function = CmmLit $ CmmLabel $ fromJust cont_id + needs_header_set = + case (curr_id, cont_id) of + (Just x, Just y) -> x /= y + _ -> isJust cont_id + +-- Lazy adjustment of stack headers assumes all blocks +-- that could branch to eachother (i.e. control blocks) +-- have the same stack format (this causes a problem +-- only for proc-point). +function_entry :: ContinuationFormat -> [CmmStmt] +function_entry (ContinuationFormat formals _ _ live_regs) + = load_live_values ++ load_args where + -- TODO: only save variables when actually needed + -- (may be handled by latter pass) + load_live_values = + [stack_get 0 reg offset + | (reg, offset) <- curr_offsets] + load_args = + [stack_get 0 reg offset + | (reg, StackParam offset) <- argument_formats] ++ + [global_get reg global + | (reg, RegisterParam global) <- argument_formats] + + argument_formats = assignArguments (localRegRep) formals + + -- TODO: eliminate copy/paste with pack_continuation + curr_offsets = mkOffsets label_size live_regs + + label_size = 1 :: WordOff + + mkOffsets size [] = [] + mkOffsets size (Nothing:regs) = mkOffsets (size+1) regs + mkOffsets size (Just reg:regs) = (reg, size):mkOffsets (size + width) regs + where + width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE + -- TODO: it would be better if we had a machRepWordWidth + +----------------------------------------------------------------------------- +-- Section: Stack and argument register puts and gets +----------------------------------------------------------------------------- +-- TODO: document + +-- |Construct a 'CmmStmt' that will save a value on the stack +stack_put :: WordOff -- ^ Offset from the real 'Sp' that 'offset' + -- is relative to (added to offset) + -> CmmExpr -- ^ What to store onto the stack + -> WordOff -- ^ Where on the stack to store it + -- (positive <=> higher addresses) + -> CmmStmt +stack_put spRel expr offset = + CmmStore (CmmRegOff spReg (wORD_SIZE*(spRel + offset))) expr + +-------------------------------- +-- |Construct a +stack_get :: WordOff + -> LocalReg + -> WordOff + -> CmmStmt +stack_get spRel reg offset = + CmmAssign (CmmLocal reg) + (CmmLoad (CmmRegOff spReg (wORD_SIZE*(spRel + offset))) + (localRegRep reg)) +global_put :: CmmExpr -> GlobalReg -> CmmStmt +global_put expr global = CmmAssign (CmmGlobal global) expr +global_get :: LocalReg -> GlobalReg -> CmmStmt +global_get reg global = CmmAssign (CmmLocal reg) (CmmReg (CmmGlobal global)) -- 1.7.10.4